PaintTheMap: A Simple Web Interface for Geospatial Analysis and Dashboards
2021-10-01, 10:00–10:30, Humahuaca

When designers think through a design, most reach for a pencil. Today it might be a $100 digital pencil, but the direct expression offered by sketch tools can offer an advantage over more sophisticated tools: it frees us from the burden of thinking about how to use the tool at hand, and lets us focus mental energy on the problem. What if we could bring the same simplicity to exploring spatial models? PaintTheMap is a web-based tool that provides a simple interface for rapidly testing ideas connected to data: sketch a quick idea and you’ll get instant feedback on the areas you’ve painted. Each paint color can be classified (eg. land use categories) and measurements are updated in real time.

PaintTheMap is a slippy-map based solution that supports painting anywhere on a map across multiple zoom levels. Painted pixels can be used for take-offs to inform numeric models - or combined with raster data in real-time to run analysis.

Under the hood, PaintTheMap uses a canvas that lets the user draw in screen-space over any map. As soon as the brush stroke is completed the ‘paint’ is transferred into any map tiles beneath the canvas on the current layer and areas are recalculated. When the user adjusts the map, the reverse happens: paint from the map tiles is transferred onto the drawing canvas. The result is a seamless, global painting experience that understands the scale of each pixel.

In this presentation, we’ll show examples of how we’ve integrated the tool via an iFrame into a calculator for embodied carbon and share further customizations including providing an easy way to identify flooded areas and combining the painted tiles with GeoJSON to quickly test development strategies.

We will outline the basic mechanics of our approach as well as discussing the challenges and limitations of our tile-based solution. You’ll learn how to set up a new instance of PaintTheMap and build it into web-based analysis tools.

See for source code and more information.

Authors and Affiliations

Ken Goulding (Sasaki)




Software/Project development


1 - Principiants. No required specific knowledge is needed.

Language of the Presentation


Ken is a Principal at Sasaki, an internationally recognized multi-disciplinary design firm. Trained in architecture and planning, Ken has dedicated his career to finding the most pertinent applications of technology to planning and design, and he remains actively involved in inventing, prototyping, and building new tools and approaches.

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